European Journal of Organic Chemistry

Cover image for Vol. 2014 Issue 24

Early View (Online Version of Record published before inclusion in an issue)

Editor: Haymo Ross, Deputy Editor: Susan Wilkinson

Impact Factor: 3.154

ISI Journal Citation Reports © Ranking: 2013: 14/58 (Chemistry Organic)

Online ISSN: 1099-0690

Associated Title(s): Advanced Synthesis & Catalysis, Asian Journal of Organic Chemistry

VIEW

  1. 1 - 96
  1. Full Papers

    1. Atropisomerism

      A Planar-Chiral Phosphino(alkenyl)ferrocene for Suzuki–Miyaura C–C Coupling Reactions

      Dieter Schaarschmidt, Martin Grumbt, Alexander Hildebrandt and Heinrich Lang

      Article first published online: 22 AUG 2014 | DOI: 10.1002/ejoc.201402861

      Thumbnail image of graphical abstract

      Planar-chiral phosphino(alkenyl)ferrocene 4 was applied in the presence of [Pd2(dba)3] in Suzuki–Miyaura C–C coupling reactions for the atropselective synthesis of sterically congested biaryls with up to four substituents in the ortho-positions. The air-stable catalytic system is excellently suited for the synthesis of tri-ortho-substituted biaryls under mild conditions (0.1 mol-%, 50–100 °C).

    2. Fused Heterocycles

      A K2CO3-Mediated Regioselective Synthesis of Indole/Pyrrole-Fused 1,4-Oxazines: An Unexpected Indole-Fused Azlactone Synthesis

      Jaya Kishore Vandavasi, Wan-Ping Hu, Gopal Chandru Senadi, Siva Senthil Kumar Boominathan, Hsing-Yin Chen and Jeh-Jeng Wang

      Article first published online: 22 AUG 2014 | DOI: 10.1002/ejoc.201402818

      Thumbnail image of graphical abstract

      A regioselective, base-catalyzed 6-exo-dig cyclization has been developed for the synthesis of indole- and pyrrole-fused 1,4-oxazines. In addition, an unprecedented one-pot hydroamination reaction was observed to occur with high chemo- and regioselectivity in the presence of base to afford indole-fused azlactones.

    3. Atroposelectivity

      A Concise Atroposelective Formal Synthesis of (–)-Steganone

      Boubacar Yalcouye, Sabine Choppin, Armen Panossian, Frédéric R. Leroux and Françoise Colobert

      Article first published online: 21 AUG 2014 | DOI: 10.1002/ejoc.201402761

      Thumbnail image of graphical abstract

      A highly atroposelective formal synthesis of (–)-steganone is described highlighting the use of an enantiopure sulfoxide as a chiral auxiliary in the Suzuki–Miyaura cross-coupling reaction.

    4. Asymmetric Catalysis

      Organocatalytic Enantioselective Strecker Reaction of Imines Containing a Thiazole Moiety by Using a Cinchona-Based Squaramide Catalyst

      Hai-Xiao He and Da-Ming Du

      Article first published online: 21 AUG 2014 | DOI: 10.1002/ejoc.201402764

      Thumbnail image of graphical abstract

      An organocatalytic enantioselective Strecker reaction was developed for the synthesis of α-amino nitriles that contain a thiazole moiety by using a cinchona-based squaramide catalyst. The corresponding products were obtained in good to excellent yields (up to 99 %) with excellent enantioselectivities (up to 98 % ee) by starting from aromatic-substituted imines.

    5. Star-Shaped Compounds

      Modular Syntheses of Star-Shaped Pyridine, Bipyridine, and Terpyridine Derivatives by Employing Sonogashira Reactions

      Daniel Trawny, Valentin Kunz and Hans-Ulrich Reissig

      Article first published online: 21 AUG 2014 | DOI: 10.1002/ejoc.201402778

      Thumbnail image of graphical abstract

      Modular, simple, and efficient! A library of C3-symmetrical compounds with benzene cores and pyridine, bipyridine, and terpyridine end groups were prepared from simple precursors.

  2. Short Communications

    1. Alkene Hydrosilylation

      Rhodium-Catalyzed Alkene Hydrosilylation via a Hydride Shuttle Process by Diene Ligands: Dramatic Enhancement of Regio- and Diastereoselectivity

      Yuanda Hua, Hiep H. Nguyen, Gabriela Trog, Adam S. Berlin and Junha Jeon

      Article first published online: 21 AUG 2014 | DOI: 10.1002/ejoc.201402742

      Thumbnail image of graphical abstract

      A cooperative functional diene ligand and a supporting phosphine ligand mediated, Rh-catalyzed intramolecular alkene hydrosilylation of homoallylic silyl ethers was developed to provide 1,3-trans-oxasilacyclopentanes in a highly regio- and diastereoselective manner. A diene ligand mediated hydride shuttle process is proposed as the mechanistic driving force behind the high level of selectivities.

  3. Full Papers

    1. Atropisomerism and Catalysis

      Tropos Amino Alcohol Mediated Enantioselective Aryl Transfer Reactions to Aromatic Aldehydes

      Laura Pisani, Carmela Bochicchio, Stefano Superchi and Patrizia Scafato

      Article first published online: 21 AUG 2014 | DOI: 10.1002/ejoc.201402702

      Thumbnail image of graphical abstract

      An application of new amino alcohols that possess a flexible biphenylazepine moiety and can function as tropos catalysts, is presented. In these compounds, the stereogenic center close to the flexible fragment induces a preferred axial chirality and determines the stereochemical outcome of asymmetric reactions. Their efficiency has been explored in the asymmetric arylation of aldehydes.

    2. Natural Product Synthesis

      Flexible Synthesis of Planar Chiral Azoninones and Optically Active Indolizidinones

      Frank Bohland, Irina Erlin, Lukas Platte, Maike Schröder, Dieter Schollmeyer and Udo Nubbemeyer

      Article first published online: 21 AUG 2014 | DOI: 10.1002/ejoc.201402720

      Thumbnail image of graphical abstract

      L-Proline derivatives were used to synthesise optically active 2-vinylpyrrolidines with E and Z double bonds. Zwitterionic aza-Claisen rearrangements led to planar chiral azoninones with defined configurations, which served as key intermediates for the synthesis of indolizidinones with up to five stereogenic centres.

    3. Enzymatic Transesterification

      Diesterification of 3-[(β-Cyclodextrinyl)succinamido]propane-1,2-diol Catalysed by Lipase: Diastereoselectivity or Tridimensional Substrate Specificity?

      Cédric Gervaise, Véronique Bonnet, Florian Nolay, Christine Cézard, Imane Stasik, Catherine Sarazin and Florence Djedaïni-Pilard

      Article first published online: 20 AUG 2014 | DOI: 10.1002/ejoc.201402414

      Thumbnail image of graphical abstract

      Two diastereoisomers of 3-[(β-cyclodextrinyl)succinamido]propane-1,2-diol have been transesterified with fatty esters and immobilized lipase from Mucor miehei. They react with different conversions, contrary to their analogues without cyclodextrins. The hydrogen bonds in the three-dimensional structures, which account for this phenomenon, are revealed by molecular modelling and NMR studies.

    4. Silica-Supported Catalysts

      Rhodium-NHC Hybrid Silica Materials as Recyclable Catalysts for [2+2+2] Cycloaddition Reactions of Alkynes

      Martí Fernández, Meritxell Ferré, Anna Pla-Quintana, Teodor Parella, Roser Pleixats and Anna Roglans

      Article first published online: 20 AUG 2014 | DOI: 10.1002/ejoc.201402649

      Thumbnail image of graphical abstract

      Hybrid silica materials derived from rhodium(I) complexes bearing an N-heterocyclic carbene ligand are obtained either by sol-gel or grafting processes. The materials are fully characterized by solid state NMR, N2-sorption measurements, thermogravimetric analysis and elemental analysis; their catalytic activity and recyclability are also evaluated in the [2+2+2] cycloaddition of alkynes.

    5. Carbonylation

      Stereoselective Synthesis of α-Alkylidene β-Oxo Amides by Palladium-Catalyzed Carbonylation

      Serena Perrone, Antonio Salomone, Antonio Caroli, Aurelia Falcicchio, Cinzia Citti, Giuseppe Cannazza and Luigino Troisi

      Article first published online: 20 AUG 2014 | DOI: 10.1002/ejoc.201402666

      Thumbnail image of graphical abstract

      A Pd-catalyzed carbonylation of α-chloro ketones in the presence of imines leads to α-alkylidene β-oxo amides in good yields. This one-pot synthetic method is highly stereoselective and affords amides only as (Z) isomers. This work increases the potential of Pd-catalyzed reactions in the direct synthesis of carbonyl compounds.

    6. Organochalcogenides

      A Recyclable Biphasic System for Stereoselective and Easily Handled Hydrochalcogenations

      Caterina Tidei, Luca Sancineto, Luana Bagnoli, Benedetta Battistelli, Francesca Marini and Claudio Santi

      Article first published online: 20 AUG 2014 | DOI: 10.1002/ejoc.201402668

      Thumbnail image of graphical abstract

      Vinyl selenides and vinyl sulfides were prepared by hydrochalcogenation of alkynes with selenols and thiols generated in situ by the reduction of the corresponding diselenides and disulfides with elemental zinc in a biphasic acidic medium. The stereoselectivity and the possibility of reusing the aqueous medium up to ten times are discussed.

    7. Heterocyclic Ketene Aminals

      Isomerization of Ninhydrin–Heterocyclic Ketene Aminal Adducts: Kinetic versus Thermodynamic Control, Solvent Dependency and Mechanism

      Nanyang Chen, Minming Zou, Xue Tian, Fengjuan Zhu, Danping Jiang, Jiagao Cheng, Xusheng Shao and Zhong Li

      Article first published online: 20 AUG 2014 | DOI: 10.1002/ejoc.201402677

      Thumbnail image of graphical abstract

      The first example of isomerization of ninhydrin–heterocyclic ketene aminals adducts is reported. The isomerization shows large solvent dependency and provides an efficient method with which to access hitherto undisclosed indeno[2,1-b]pyrrol-8(1H)-ones. Reaction products can now be regulated based on kinetic and thermodynamic selection principles.

    8. Synthetic Methods

      Development and Optimization of Simple One-Step Methods for the Synthesis of 4-Amino-Substituted 1,8-Naphthalimides

      Tomas Kindahl, Elin Chorell and Erik Chorell

      Article first published online: 20 AUG 2014 | DOI: 10.1002/ejoc.201402684

      Thumbnail image of graphical abstract

      One-step methods for the synthesis of 4-amino-substituted 1,8-naphthalimides have been developed and optimized by using multivariate studies of temperature, reaction time and equivalents of substrates. The identified conditions could successfully be applied to generate various 4-amino-substituted 1,8-naphthalimides in high yields.

    9. Carbohydrate Vaccines

      A Strategy for Multivalent Presentation of Carba Analogues from N. meningitidis A Capsular Polysaccharide

      Daniela Ramella, Laura Polito, Stefania Mazzini, Silvia Ronchi, Leonardo Scaglioni, Marcello Marelli and Luigi Lay

      Article first published online: 20 AUG 2014 | DOI: 10.1002/ejoc.201402701

      Thumbnail image of graphical abstract

      Carba analogues of fragments of the N. meningitidis A polysaccharide have been proposed as hydrolytically stable analogues that have immunological activity in mice. Using the MRI technique, we found that when the carba analogues are loaded onto the surface of iron oxide nanoparticles, they show a multivalent effect that enhances their ability to be recognised by MenA antiserum.

    10. Natural Product Reassignment

      Toward the Total Synthesis of Klaivanolide: Complete Reinterpretation of Its Originally Assigned Structure

      Laurent Ferrié, Sabrina Ferhi, Guillaume Bernadat and Bruno Figadère

      Article first published online: 20 AUG 2014 | DOI: 10.1002/ejoc.201402741

      Thumbnail image of graphical abstract

      Attempts towards the total synthesis of uncommon seven-membered ring lactone klaivanolide led us to revise its original structural assignment. The isolated compound was revealed to be a known molecule, the five-membered ring acetylmelodorinol.

    11. Cytotoxic Nucleosides

      Trifluoromethylated Nucleosides: A Building Block Approach to Cytotoxic Adenosine Analogues

      Johannes Drexler and Ulrich Groth

      Article first published online: 20 AUG 2014 | DOI: 10.1002/ejoc.201402755

      Thumbnail image of graphical abstract

      Adenosine analogues based on the 7-deazapurine motif were synthesized using synthons, allowing for introduction of a diverse set of substituents, including fluorinated moieties. Analogue cytotoxicities were determined against HeLa S3 and Hep G2 cancer cell lines and compared with the structurally similar agent tubercidin; one lead structure with nM bioactivity was identified.

    12. Peptidic Gelators

      Turning Around the L-Phe-D-Oxd Moiety for a Versatile Low-Molecular-Weight Gelator

      Lorenzo Milli, Nicola Castellucci and Claudia Tomasini

      Article first published online: 20 AUG 2014 | DOI: 10.1002/ejoc.201402787

      Thumbnail image of graphical abstract

      A small library of 13 peptidomimetics have been prepared and tested as gelators in a plethora of solvents and solvent mixtures. Two molecules were very efficient, Boc-L-Phe-D-Oxd-L-Phe-OBn and Fmoc-L-Phe-D-pGlu-OH, which also efficiently gelated phosphate-buffered saline. A rationale to explain the different behaviour of these peptidomimetics takes into consideration their hydrophobicity.

  4. Short Communications

    1. Regioselective Cascade Reactions

      Tunable Base-Controlled Regioselective Cascade Reaction of 2-Mercaptobenzimidazole with Morita–Baylis–Hillman Acetates of Nitroalkenes

      Jia-Qiang Zhang, Jie-Jie Liu, Chun-Ling Gu, Dong Wang and Li Liu

      Article first published online: 20 AUG 2014 | DOI: 10.1002/ejoc.201402752

      Thumbnail image of graphical abstract

      Two series of heterocyclic compounds, thiazolo[3,2-a]benzimidazoles and benzimidazo[2,1-b]-1,3-thiazines, are synthesized by the tunable base-controlled regioselective cascade reaction of 2-mercaptobenzimidazole with Morita–Baylis–Hillman acetates of nitroalkenes in good yields with high regioselectivities. DBU = 1,8-diazabicyclo[5.4.0]undec-7-ene.

  5. Full Papers

    1. Organocatalysis

      Properties and Reactivity of Conformationally Constrained Bicyclic Diarylprolinol Silyl Ethers as Organocatalysts

      Marco Lombardo, Lucia Cerisoli, Elisabetta Manoni, Elisa Montroni, Arianna Quintavalla and Claudio Trombini

      Article first published online: 19 AUG 2014 | DOI: 10.1002/ejoc.201402732

      Thumbnail image of graphical abstract

      Bicyclic silyl ether derivative 1a, which is easily prepared from trans-4-L-hydroxyproline, is much more stable toward protodesilylation than Jørgensen–Hayashi's catalyst 2a. Despite their structural analogy, 1a behaves as a very efficient catalyst in iminium chemistry, but is much less active than 2a in the enamine activation mode. Here, 1a exhibits a higher or equivalent level of stereocontrol.

    2. Organogelators

      Linear Oligocarbazole-Based Organogelators: Synthesis and Fluorescent Probing of Explosives

      Guanghui Hong, Chong Qian, Pengchong Xue, Xingliang Liu, Qingqing Wang, Mingyang Liu, Peng Gong and Ran Lu

      Article first published online: 18 AUG 2014 | DOI: 10.1002/ejoc.201402565

      Thumbnail image of graphical abstract

      The first simple carbazole-based organogelator C1 has been synthesized and can self-assemble into nanofibers through π–π interactions. Moreover, the new linear carbazole-based trimer C3 and pentamer C5 with extended conjugation also formed gels in some organic solvents upon ultrasound stimulation, and blue-emitting nanofibers based on C3 detected vapors of TNT and DNT by fluorescent quenching.

    3. Regioselectivity Switching

      Palladium-Catalyzed Regioselective 5-exo-O-Cyclization/Oxidative Heck Cascades from o-Alkynylbenzamides and Electron-Deficient Alkenes

      Youssef Madich, Rosana Álvarez and José M. Aurrecoechea

      Article first published online: 15 AUG 2014 | DOI: 10.1002/ejoc.201402709

      Thumbnail image of graphical abstract

      Oxycyclization/oxidative Heck cascade reactions between o-alkynylbenzamides and electron-deficient alkenes have a cyclization regiochemistry that is catalyst dependent. Thus, the 6-endo-regioselectivity reported for a PdCl2(PPh3)2 catalyst becomes a preference for 5-exo-products when Pd(OAc)2 is used.

    4. Perfluoroalkylation

      A General, Regiospecific Synthetic Route to Perfluoroalkylated Arenes via Arene­diazonium Salts with RFCu(CH3CN) Complexes

      Dong-Fang Jiang, Chao Liu, Yong Guo, Ji-Chang Xiao and Qing-Yun Chen

      Article first published online: 15 AUG 2014 | DOI: 10.1002/ejoc.201402820

      Thumbnail image of graphical abstract

      Acetonitrile is used as a ligand to stabilize perfluorocopper species by forming RFCu(CH3CN) complexes. Arenediazonium salts successfully react with this complex, leading to the regiospecific perfluoroalkylation of arenes. A wide range of functional groups are tolerated in the reaction.

  6. Short Communications

    1. Iodocyclization

      Copper(I) Iodide Mediated Iodocyclization of Cyclopropylideneallenyl Ketones: Facile and Effective Synthesis of Highly Substituted Furan Derivatives

      Maozhong Miao, Xin Xu, Lijun Xu and Hongjun Ren

      Article first published online: 15 AUG 2014 | DOI: 10.1002/ejoc.201402823

      Thumbnail image of graphical abstract

      A I2/CuI system promotes the iodocyclization of cyclopropylideneallenyl ketones to produce highly substituted furans under mild conditions. The resulting furans can be transformed into some advanced furan derivatives through nucleophilic substitution and the Pd-catalyzed Suzuki cross-coupling reaction.

    2. Suzuki Coupling

      General Suzuki Coupling of Heteroaryl Bromides by using Tri-tert-butylphosphine as a Supporting Ligand

      Yinjun Zou, Guizhou Yue, Jianwei Xu and Jianrong (Steve) Zhou

      Article first published online: 15 AUG 2014 | DOI: 10.1002/ejoc.201402915

      Thumbnail image of graphical abstract

      A fast, general coupling of heteroaryl bromides is realized by using a single palladium catalyst supported by tri-tert-butylphosphine.

  7. Full Papers

    1. Oxidative Coupling

      Ionic-Liquid-Assisted Metal-Free Oxidative Coupling of Amines To Give Imines

      Antonio Monopoli, Pietro Cotugno, Francesco Iannone, Francesco Ciminale, Maria Michela Dell'Anna, Piero Mastrorilli and Angelo Nacci

      Article first published online: 15 AUG 2014 | DOI: 10.1002/ejoc.201402530

      Thumbnail image of graphical abstract

      An oxidative coupling of amines to give imines in ionic liquids (ILs) under metal-free aerobic conditions has been developed. The efficiency achievable in ILs is explained in terms of activation of the reactants (benzylamine and O2) by an initial electron transfer, promoted by the ionic medium.

    2. Total Synthesis

      Total Synthesis of a Pyrrole Lactone Alkaloid, Longanlactone

      Chada Raji Reddy, Motatipally Damoder Reddy and Uredi Dilipkumar

      Article first published online: 15 AUG 2014 | DOI: 10.1002/ejoc.201402563

      Thumbnail image of graphical abstract

      The first total synthesis of a new pyrrole lactone alkaloid, longanlactone, along with its C-4 epimer is achieved from the natural amino acid L-aspartic acid with a Barbier-type propargylation and a Paal–Knorr pyrrole synthesis as key steps.

    3. Natural Product Synthesis

      Asymmetric Formal Synthesis of (+)-­Lactacystin

      Chirumarry Sridhar, Bodduri V. D. Vijaykumar, Laghuvarapu Radhika, Dong-Soo Shin and Srivari Chandrasekhar

      Article first published online: 15 AUG 2014 | DOI: 10.1002/ejoc.201402700

      Thumbnail image of graphical abstract

      A formal synthesis of (+)-lactacystin was achieved from readily available isobutyraldehyde and ethyl acrylate by using a Baylis–Hillman reaction, an intermolecular nucleophilic displacement under Mitsunobu conditions, a Sharpless asymmetric epoxidation, a palladium-catalyzed syn-selective ring opening of an epoxide, an azide reductive lactamization, and a ruthenium-catalyzed oxidation as the key steps.

    4. Enzyme Inhibitors

      Synthesis of Cyclophellitol, Cyclophellitol Aziridine, and Their Tagged Derivatives

      Kah-Yee Li, Jianbing Jiang, Martin D. Witte, Wouter W. Kallemeijn, Hans van den Elst, Chung-Sing Wong, Sharina D. Chander, Sascha Hoogendoorn, Thomas J. M. Beenakker, Jeroen D. C. Codée, Johannes M. F. G. Aerts, Gijs A. van der Marel and Herman S. Overkleeft

      Article first published online: 14 AUG 2014 | DOI: 10.1002/ejoc.201402588

      Thumbnail image of graphical abstract

      The syntheses of cyclophellitol and of cyclophellitol aziridine from a common intermediate are described. Optimization of the construction of this building block, previously described by Madsen, enables the synthesis of both title compounds. Azide groups are introduced into both cyclitol cores to allow click ligation to a variety of tags, thus yielding a series of retaining glucosidase probes.

    5. Cyclophellitol Derivatives

      Synthesis of α- and β-Galactopyranose-Configured Isomers of Cyclophellitol and Cyclophellitol Aziridine

      Lianne I. Willems, Thomas J. M. Beenakker, Benjamin Murray, Berend Gagestein, Hans van den Elst, Erwin R. van Rijssel, Jeroen D. C. Codée, Wouter W. Kallemeijn, Johannes M. F. G. Aerts, Gijsbert A. van der Marel and Herman S. Overkleeft

      Article first published online: 14 AUG 2014 | DOI: 10.1002/ejoc.201402589

      Thumbnail image of graphical abstract

      The synthesis of α- and β-galactopyranose-configured derivatives of cyclophellitol and of cyclophellitol aziridine, either non-tagged or functionalized with various reporter entities, is described. All epoxide- and aziridine-based compounds are synthesized from a single cyclohexene precursor – (3S,4S,5S,6R)-3,4-dibenzyloxy-5-hydroxy-6-(hydroxymethyl)cyclohex-1-ene.

    6. Two-Photon Chromophores

      Synthesis and Two-Photon Absorption Properties of Ladder-Type Chromophores with Functionalized Pyrazine Units Fused as the End-Groups

      Tzu-Chau Lin, Bo-Kai Tsai, Yi-You Liu and Ming-Yu Tsai

      Article first published online: 14 AUG 2014 | DOI: 10.1002/ejoc.201402622

      Thumbnail image of graphical abstract

      Three multipolar chromophores based on ladder-type units as the central π-bridges with functionalized pyrazine moieties fused as the end-groups were synthesized for study of two-photon absorption (2PA). The π-conjugation length of the central oligo-p-phenylene component is closely related to the magnitude of 2PA, and such a structural motif provides access to highly efficient nonlinear absorbers.

    7. Fullerene Derivatives

      Reactions of [60]Fullerene with Halides and Amino Acids to Synthesize Fullero­pyrrolidines

      Bo Jin, Juan Shen, Rufang Peng, Congdi Chen and Shijin Chu

      Article first published online: 14 AUG 2014 | DOI: 10.1002/ejoc.201402655

      Thumbnail image of graphical abstract

      Fulleropyrrolidines bearing ArCH moieties were obtained in reactions between C60, the appropriate benzyl chlorides, and amino acids. A detailed investigation of these reactions resulted in the discovery of other halides, such as allyl chlorides, propargyl bromides, ethyl bromoacetate, bromoacetonitrile, and alkyl bromides, that also reacted with C60 and amino acids to produce fulleropyrrolidines.

    8. 1,3-Dipolar Cycloaddition

      Stereoselective Synthesis of Enantiopure Cycloalkylglycines by 1,3-Dipolar Cycloaddition of a Chiral Nitrone to Cycloalkenes

      Heithem Abda, Kaïss Aouadi, Lionel Perrin, Moncef Msaddek, Jean-Pierre Praly and Sébastien Vidal

      Article first published online: 12 AUG 2014 | DOI: 10.1002/ejoc.201402842

      Thumbnail image of graphical abstract

      The 1,3-dipolar cycloaddition of a (–)-menthone-derived nitrone to cycloalkenes afforded isoxazolidines in high yields and with high stereoselectivity. After a one-pot cleavage of the N–O, amide, and N–C–N bonds, the cycloadducts led to α-amino lactones. Subsequent hydrolysis provided enantiopure cycloalkylglycine derivatives in good overall yields (>40 %).

  8. Short Communications

    1. Spirooxindoles

      Highly Enantioselective Construction of Polycyclic Spirooxindoles by Organocatalytic 1,3-Dipolar Cycloaddition of 2-Cyclohexenone Catalyzed by Proline-Sulfonamide

      Jun-An Xiao, Qi Liu, Ji-Wei Ren, Jian Liu, Rich G. Carter, Xiao-Qing Chen and Hua Yang

      Article first published online: 11 AUG 2014 | DOI: 10.1002/ejoc.201402953

      Thumbnail image of graphical abstract

      The highly enantioselective construction of polycyclic spirooxindoles through 1,3-dipolar cycloaddition of cyclohexenone with azomethine ylides is achieved by employing prolinosulfonamides as the catalyst. This catalytic system essentially benefits from iminium activation and hydrogen-bonding formation induced by the prolinosulfonamides.

  9. Full Papers

    1. Cyanophenol Synthesis

      Facile One-Pot Transformation of Phenols into o-Cyanophenols

      Yuhta Nakai, Katsuhiko Moriyama and Hideo Togo

      Article first published online: 11 AUG 2014 | DOI: 10.1002/ejoc.201402817

      Thumbnail image of graphical abstract

      Various phenols were treated with MgCl2, Et3N, and paraformaldehyde in THF, followed by reaction with molecular iodine and aq. ammonia to provide the corresponding o-cyanophenols in a one-pot manner.

  10. Short Communications

    1. Helical Imidazolia

      Modular Synthesis of Helicene-Like Compounds Based on the Imidazolium Motif

      Martina Čížková, David Šaman, Dušan Koval, Václav Kašička, Blanka Klepetářová, Ivana Císařová and Filip Teplý

      Article first published online: 7 AUG 2014 | DOI: 10.1002/ejoc.201402746

      Thumbnail image of graphical abstract

      Straightforward assembly of helicene-like cationic systems based on the imidazolium core is introduced. The strategy takes advantage of double [2+2+2] cycloaddition reactions and opens rapid four-step access to a cationic helical species featuring nine ortho-annulated rings.

  11. Full Papers

    1. Enhanced Catalytic Activity

      Synergistic Effect of a Bis(proazaphosphatrane) in Mild Palladium-Catalyzed Direct α-Arylations of Nitriles with Aryl Chlorides

      So Han Kim, Wonseok Jang, Min Kim, John G. Verkade and Youngjo Kim

      Article first published online: 6 AUG 2014 | DOI: 10.1002/ejoc.201402466

      Thumbnail image of graphical abstract

      The effect of a bis(proazaphosphatrane) ligand on the palladium-catalyzed direct α-arylation of nitriles with various aryl chlorides under mild conditions was investigated. Three related mono(proazaphosphatrane) analogues were employed under the same reaction conditions as a comparison to reveal the enhanced catalytic activity of the bis(proazaphosphatrane) ligand.

    2. Flow Chemistry

      An Efficient Partial Reduction of α,β-Unsaturated Esters Using DIBAL-H in Flow

      Masahito Yoshida, Hiroyuki Otaka and Takayuki Doi

      Article first published online: 6 AUG 2014 | DOI: 10.1002/ejoc.201402675

      Thumbnail image of graphical abstract

      The partial reduction of α,β-unsaturated esters and benzoate derivatives to form the corresponding aldehydes was achieved using a flow reactor system within 1 s at a high flow rate (18 mL min–1) under cryogenic conditions (–97 °C). Commercially available diisobutylaluminium hydride (DIBAL-H) was used as the reductant.

    3. Chiral Allenes

      Zinc Salt Promoted Diastereoselective Synthesis of Chiral Propargylamines Using Chiral Piperazines and Their Enantioselective Conversion into Chiral Allenes

      Mariappan Periasamy, Polimera Obula Reddy, Athukuri Edukondalu, Manasi Dalai, Laxman M. Alakonda and Bantu Udaykumar

      Article first published online: 6 AUG 2014 | DOI: 10.1002/ejoc.201402766

      Thumbnail image of graphical abstract

      A series of chiral piperazine derivatives has been prepared for use in the synthesis of chiral propargylamines for their enantioselective conversion into chiral allenes. The facile cyclodimerization of aryl-substituted allenes suggests ways to overcome the difficulties in handling and storing chiral aryl-substituted allenes.

    4. Oxidative C–H Amination

      A Unified Strategy Towards N-Aryl Heterocycles by a One-Pot Copper-Catalyzed Oxidative C–H Amination of Azoles

      Parthasarathi Subramanian and Krishna P. Kaliappan

      Article first published online: 5 AUG 2014 | DOI: 10.1002/ejoc.201402868

      Thumbnail image of graphical abstract

      An efficient one-pot synthesis of N-aryl heterocycles by a Cu-catalysed double C–N bond formation is reported. This strategy involves a CuI-catalysed C–N bond-forming reaction between azoles and electron-deficient bromopyridines followed by an intramolecular sp2 C–H amination.

    5. Multicomponent Reactions

      Diversity-Oriented Synthesis of Polycyclic Indoles: Brønsted or Lewis Acid Catalyzed Three-Component Reaction for the Synthesis of α-Carbolines and Pyrimidoindoles

      Rajesh K. Arigela, Ravi Kumar, Srinivas Samala, Sahaj Gupta and Bijoy Kundu

      Article first published online: 5 AUG 2014 | DOI: 10.1002/ejoc.201402633

      Thumbnail image of graphical abstract

      We report the diversity-oriented synthesis of pyrido- and pyrimido-indoles from an acid-catalyzed three-component (3C) reaction involving ethyl 2-amino-1H-indole-3-carboxylates, arylaldehydes, and terminal alkynes. With a Brønsted acid, the 3C reaction furnished a mixture of pyrido- and pyrimido-indoles, whereas when a Lewis acid was used, pyrimidoindoles were obtained as the single product.

    6. Donor–Acceptor Systems

      Donor–Acceptor 1,4-Fluorenylene Chromophores: Photophysics, Electrochemistry, and Synthesis through a Route for Asymmetric Chromophore Preparation

      Brynna J. Laughlin, Mary K. Burdette, Chadwick R. Powell, Benjamin E. Levy, Andrew G. Tennyson and Rhett C. Smith

      Article first published online: 5 AUG 2014 | DOI: 10.1002/ejoc.201402181

      Thumbnail image of graphical abstract

      A convenient route for the asymmetric derivatization of 1,4-phenylene and 1,4-fluorenylene cores is reported and applied to the preparation of fourteen chromophores. The chromophores were examined by electrochemical techniques, photophysical studies, and DFT calculations.

  12. Short Communications

    1. Asymmetric Allylic Alkylation

      First Example of the Intermolecular Palladium-Catalyzed Asymmetric Allylic Alkylation of Hydroxyacrylates: Synthesis of All-Carbon α-Aryl Quaternary Aldehydes

      Sharif A. Asad, Joseph Ulicki, Maria Shevyrev, Nazim Uddin, Eduardo Alberch and M. Mahmun Hossain

      Article first published online: 5 AUG 2014 | DOI: 10.1002/ejoc.201402911

      Thumbnail image of graphical abstract

      A strategy for the Pd-catalyzed asymmetric allylic alkylation reaction is developed, in which hydroxylarylacrylates are used as nucleophiles instead of widely used ketones to provide a number of very rare acyclic all-carbon α-aryl quaternary aldehydes. The formation of multiple isomeric enolates can be avoided in this protocol, while maintaining step economy and substrate unbiasedness.

    2. Oxidative Coupling

      Copper-Catalyzed Synthesis of Thiosulfonates by Oxidative Coupling of Thiols with Sodium Sulfinates

      Nobukazu Taniguchi

      Article first published online: 5 AUG 2014 | DOI: 10.1002/ejoc.201402847

      Thumbnail image of graphical abstract

      The copper-catalyzed sulfonylation of thiols is performed by using sodium sulfinates under an oxygen atmosphere to afford the corresponding thiosulfonates in good yields. The procedure tolerates numerous combinations of arene- and alkanethiols with sodium sulfinates. Phen = 1,10-phenanthroline.

  13. Microreviews

    1. Lithiated Small Heterocycles

      Complexation Phenomena and Dynamics at Work in the Lithiation Reactions of Small-Ring Heterocycles: Regio- and Stereoselectivity

      Vito Capriati, Saverio Florio and Renzo Luisi

      Article first published online: 5 AUG 2014 | DOI: 10.1002/ejoc.201402744

      Thumbnail image of graphical abstract

      This Microreview focuses on the regio- and stereoselective preparation of α- and ortho-lithiated oxiranes, aziridines, oxetanes, azetidines, and tetrahydrofurans with special emphasis on factors such as carbene-like character, aggregation, complexation phenomena and dynamics which strongly influence their applications to synthetic chemistry. Recent selected examples extracted from the literature are critically analysed and commented.

  14. Full Papers

    1. Fluorinated Compounds

      Ring-Closing Metathesis of Vinyl Fluorides towards α-Fluorinated α,β-Unsaturated Lactams and Lactones

      Michael Marhold, Christian Stillig, Roland Fröhlich and Günter Haufe

      Article first published online: 5 AUG 2014 | DOI: 10.1002/ejoc.201402535

      Thumbnail image of graphical abstract

      Ring-closing metathesis reactions of aza- and oxa-α,ω-dienes containing 2-fluoroacrylic and 2-fluoroallylic moieties lead to α-fluorinated α,β-unsaturated five- and six-membered lactones and lactams using Grubbs II or Hoveyda's catalysts.

    2. Tandem Reactions

      Synthesis of Pyrrolidines and Pyrroles by Tandem Amination/Cyanation/Alkylation and Amination/Oxidation Sequences

      Junbin Han, Zhichao Lu, Gerald B. Hammond and Bo Xu

      Article first published online: 1 AUG 2014 | DOI: 10.1002/ejoc.201402748

      Thumbnail image of graphical abstract

      Copper-catalyzed three-component tandem amination/cyanation/alkylation of the primary-amine-tethered alkynes 1 gives α-CN-substituted pyrrolidines 6 in good yields and regioselectivities. In addition, silver-mediated tandem amination/oxidation of the secondary-amine-tethered alkynes 7 produces functionalized pyrroles 8 in good yields.

  15. Short Communications

    1. Metathesis

      Ring-Expanding Metathesis Oligomerization of Cyclic Nitrones

      Yasushi Imada, Chiaki Okita, Hiroki Maeda, Masayuki Kishimoto, Yoshinori Sugano, Hiroyuki Kaneshiro, Yuri Nishida, Soichiro Kawamorita, Naruyoshi Komiya and Takeshi Naota

      Article first published online: 1 AUG 2014 | DOI: 10.1002/ejoc.201402859

      Thumbnail image of graphical abstract

      Medium-sized cyclic nitrones undergo ring-expanding dimerization/oligomerization (REMON) in the presence of organic or inorganic acids; up to 50-membered polynitrone ring systems are isolated. Cyclic nitrones with odd-number-membered rings are converted into dimers, whereas even-number-membered rings undergo consecutive ring-expansion reactions to afford macrocyclic polynitrones.

  16. Full Papers

    1. Protecting Groups

      4-Acetylthio-2,2-dimethyl-3-oxobutyl Group as an Esterase- and Thermo-Labile Protecting Group for Oligomeric Phosphodiesters

      Anna Leisvuori, Harri Lönnberg and Mikko Ora

      Article first published online: 1 AUG 2014 | DOI: 10.1002/ejoc.201402412

      Thumbnail image of graphical abstract

      Thymidine-derived trimers and tetramers that bear three enzymolabile and thermolabile 4-acetylthio-2,2-dimethyl-3-oxobutyl groups undergo conversion to fully deprotected phosphodiesters at pH 7.5 and 37 °C in the presence and absence of enzyme. Some degradation of the phosphate backbone takes place as a side reaction.

    2. Heterocyclic Chemistry

      One-Pot α-Amidosulfone-Mediated Variation of the Pictet–Spengler Tetrahydroisoquinoline Synthesis, Suitable for Amide-Type Substrates

      Francisco J. Arroyo, Pilar López-Alvarado, A. Ganesan and J. Carlos Menéndez

      Article first published online: 1 AUG 2014 | DOI: 10.1002/ejoc.201402487

      Thumbnail image of graphical abstract

      A one-pot variation of the Pictet–Spengler reaction has been developed that, unlike previous protocols, allows efficient preparation of tetrahydroisoquinolines from amide-type substrates and aldehydes. Pyrazino[2,1-b]isoquinolines, precursors to saframycin analogues, were readily prepared using this new and flexible method.

    3. Natural Products

      Immunosuppressive Diterpenes from Phomopsis sp. S12

      Wei Wei, Jian Gao, Yan Shen, Yan L. Chu, Qiang Xu and Ren X. Tan

      Article first published online: 1 AUG 2014 | DOI: 10.1002/ejoc.201402491

      Thumbnail image of graphical abstract

      Three new diterpenes, myrocin E (5), libertellenone J (6), and libertellenone K (7), were isolated from the culture of Phomopsis sp. S12. Libertellenone J (6) was shown to have most selective immunosuppressive activity and may become a lead structure candidate for the optimization of new immunosuppressants.

    4. Boron-Dipyrromethenes

      Synthesis of Hexasubstituted Boron-Dipyrromethenes Having a Different Combination of Substituents

      Vellanki Lakshmi and Mangalampalli Ravikanth

      Article first published online: 1 AUG 2014 | DOI: 10.1002/ejoc.201402599

      Thumbnail image of graphical abstract

      We have synthesized and studied the properties of hexasubstituted BODIPYs containing two different types of aryl/alkyl substituents on their pyrrole carbon atoms.

    5. Stereoconvergent Synthesis

      Stereoselective Synthesis of cis,cis-Configured Vicinal Triamines

      Adrian Schulte, Susumu Saito and Bernhard Wünsch

      Article first published online: 1 AUG 2014 | DOI: 10.1002/ejoc.201402685

      Thumbnail image of graphical abstract

      cis,cis-Configured perhydroquinoxalin-5-amines were prepared stereoselectively by means of a synthesis in which the key step was the diastereoselective reduction of an imine formed by intramolecular condensation of an amino ketone. The cis-configured amino ketone resulted from trans-to-cis isomerization after oxidation of a cis,trans-configured amino alcohol.

  17. Microreviews

    1. Solar Cell Photosensitizers

      Multi-Branched Multi-Anchoring Metal-Free Dyes for Dye-Sensitized Solar Cells

      Norberto Manfredi, Bianca Cecconi and Alessandro Abbotto

      Article first published online: 1 AUG 2014 | DOI: 10.1002/ejoc.201402422

      Thumbnail image of graphical abstract

      Multi-branched multi-anchoring organic dyes represent a recent new class of metal-free photosensitizers for dye-sensitized solar cells of increasing interest. The article describes design strategies, synthetic routes and optical and photovoltaic properties. The multi-branched geometry is able to induce unique features that in turn give rise to relevant photovoltaic properties.

  18. Full Papers

    1. Synthetic Methods

      Trimethylaluminium-Mediated Reaction of Primary Carboxamides with Amines and Indoles: A Convenient Synthesis of Amidines and Indole-3-acylimines

      A. Velavan, S. Sumathi and K. K. Balasubramanian

      Article first published online: 30 JUL 2014 | DOI: 10.1002/ejoc.201402386

      Thumbnail image of graphical abstract

      Primary carboxamides are found to be suitable substrates for trimethylaluminium-mediated one-step synthesis of N- and N,N-disubstituted amidines. By using this methodology, the synthesis of a diverse class of amidines from primary carboxamides and amines is described. The one-step synthesis of indole C3 acylimines was also demonstrated from primary carboxamides and free NH indole systems mediated by AlMe3.

    2. Palladium Nanoparticles

      Pd Nanoparticles Immobilized on Nano­silica Triazine Dendritic Polymer: A Reu­sable Catalyst for the Synthesis of Mono-, Di-, and Trialkynylaromatics by Sonogashira Cross-Coupling in Water

      Amir Landarani Isfahani, Iraj Mohammadpoor-Baltork, Valiollah Mirkhani, Ahmad R. Khosropour, Majid Moghadam and Shahram Tangestaninejad

      Article first published online: 30 JUL 2014 | DOI: 10.1002/ejoc.201402503

      Thumbnail image of graphical abstract

      Palladium nanoparticles immobilized on nano-silica triazine dendritic polymer (Pdnp-nSTDP) was found to be a highly effective catalyst for the Sonogashira cross-coupling of aryl halides (iodides, bromides, and chlorides) with aromatic and aliphatic terminal alkynes. The reaction was best performed in water as a green solvent in the presence of just 0.01 mol-% of the catalyst at room temperature.

    3. Porphyrins

      Synthesis of trans-A2B2- and trans-A2BC-Porphyrins with Polar 4′-(Dimethylamino)­tolan-4-yl Substituents, and a Screening Protocol for Vapor-Phase Deposition on Metal Surfaces

      Mariza N. Alberti, Sylwia Nowakowska, Manolis D. Tzirakis, Jan Nowakowski, Petra Fesser, W. Bernd Schweizer, Aneliia Shchyrba, Carlo Thilgen, Thomas A. Jung and François Diederich

      Article first published online: 30 JUL 2014 | DOI: 10.1002/ejoc.201402634

      Thumbnail image of graphical abstract

      In the context of exploring the role of the polar 4′-(dimethylamino)tolan-4-yl group in 3D (single crystals) and 2D [on Au(111)] self-assembly of tetraarylporphyrins, we synthesized and fully characterized a series of meso-substituted trans-porphyrins. A reliable protocol was developed to test the suitability of molecules for intact deposition on surfaces by sublimation in ultra-high vacuum.

    4. Cyclodextrins

      Controlled Acid-Mediated Regioselective O-Desilylations for Multifunctionalization of Cyclodextrins

      Jiamin Gu, Tong Chen, Ping Zhang and Chang-Chun Ling

      Article first published online: 30 JUL 2014 | DOI: 10.1002/ejoc.201402802

      Thumbnail image of graphical abstract

      A controlled acid-mediated O-desilylation method has been developed for cyclodextrin (CD) chemistry using the easily accessible per-3,6-O-silylated CD derivatives as a substrates. This method allows easy access to versatile CD intermediates that can be used for tri- or tetra-functionalizations.

  19. Short Communications

    1. Cat(alysts) Like FELIX!

      Infrared Multiphoton Dissociation Spectroscopic Analysis of Noncovalent Interactions in Organocatalysis

      Mareike C. Holland, Giel Berden, Jos Oomens, Anthony J. H. M. Meijer, Mathias Schäfer and Ryan Gilmour

      Article first published online: 30 JUL 2014 | DOI: 10.1002/ejoc.201402845

      Thumbnail image of graphical abstract

      The first application of infrared multiphoton dissociation (IRMPD) spectroscopy to study noncovalent interactions in organocatalysis is reported. Valuable insight into the interactions associated with MacMillan-catalyst-derived α,β-unsaturated iminium ions can be derived in the absence of solvent or counterions. A preliminary structure–catalysis correlation is also disclosed.

  20. Full Papers

    1. Total Synthesis

      Total Synthesis of Dictyodendrins B and E, and Formal Synthesis of Dictyodendrin C

      Pengyu Tao, Jingjing Liang and Yanxing Jia

      Article first published online: 28 JUL 2014 | DOI: 10.1002/ejoc.201402672

      Thumbnail image of graphical abstract

      The total syntheses of dictyodendrins B and E, and the formal synthesis of dictyodendrin C were completed in 9, 11, and 7 steps, respectively (longest linear sequence) from known 4′,6-dimethoxybiphenyl-2-amine. The concise strategy featured a palladium-catalysed Larock indole synthesis and a palladium-mediated one-pot consecutive Buchwald–Hartwig amination/C–H activation reaction.

    2. Annulation

      A Short-Step Synthesis of 1,6-Methano[10]annulene-3,4-dicarboximides and Their Benzene-, Naphthalene-, and Thiophene-Annulated Compounds

      Mitsunori Oda, Tomomi Nakamura, Miyako Neha, Daisuke Miyawaki, Akira Ohta, Shigeyasu Kuroda and Ryuta Miyatake

      Article first published online: 28 JUL 2014 | DOI: 10.1002/ejoc.201402776

      Thumbnail image of graphical abstract

      A new one-pot procedure for 1,6-methano[10]annulene-3,4-dicarboximides and its arene-annulated compounds is developed. Cyclohepta-1,3,5-triene-1,6-dicarbaldehyde and its arene-annulated dicarbaldehyde analogs react with various phosphorane reagents to give 1,6-methano[10]annulene-3,4-dicarboximides.

    3. Heterocyclic Chemistry

      Two-Step Synthesis of 2-Aminoindolizines from 2-Alkylpyridines

      Murat Kucukdisli and Till Opatz

      Article first published online: 28 JUL 2014 | DOI: 10.1002/ejoc.201402618

      Thumbnail image of graphical abstract

      2-Aminoindolizines have been synthesized from 2-alkylpyridines and readily available cyanohydrin triflates in two steps. This extension of the Tschitschibabin indolizine synthesis allows the introduction of various substituents at the 1-, 3-, 6-, 7-, and 8-positions and does not leave undesired electron-withdrawing groups in the products.

  21. Microreviews

    1. Hydroamination

      Efficient Anti-Markovnikov-Selective Catalysts for Intermolecular Alkyne Hydroamination: Recent Advances and Synthetic Applications

      Jacky C. -H. Yim and Laurel L. Schafer

      Article first published online: 28 JUL 2014 | DOI: 10.1002/ejoc.201402300

      Thumbnail image of graphical abstract

      Hydroamination, the catalytic addition of an N–H bond across a C–C unsaturation site, is a 100 % atom-economical route for the construction of nitrogen-containing small molecules. However, regioselectivity is a great challenge for this reaction. This Microreview focuses on recent advances and highlights some synthetic applications of anti-Markovnikov-selective intermolecular alkyne hydroamination.

  22. Full Papers

    1. Regiospecific Nitration

      Regiospecific Synthesis of Substituted 2-Nitrobenzaldehydes from Benzaldehydes through Palladium-Catalyzed Chelation-Assisted C–H Nitration

      Wei Zhang, Degui Wu, Jian Zhang and Yunkui Liu

      Article first published online: 25 JUL 2014 | DOI: 10.1002/ejoc.201402451

      Thumbnail image of graphical abstract

      An efficient and general method for the regiospecific synthesis of substituted 2-nitrobenzaldehydes from related benzaldehydes has been developed. The approach involves palladium-catalyzed chelation-assisted C–H nitration as the key step, and enables regiospecific nitration of C–H bonds free from the effect of orientation rules.

    2. Bioactive Natural Products

      Eudesmane-Type Sesquiterpenes from Curcuma phaeocaulis and Their Inhibitory Activities on Nitric Oxide Production in RAW 264.7 Cells

      Yue Liu, Jianghao Ma, Ying Wang, Paul Owusu Donkor, Qin Li, Suyu Gao, Yaguang Hou, Yang Xu, Jianing Cui, Liqin Ding, Feng Zhao, Ning Kang, Lixia Chen and Feng Qiu

      Article first published online: 25 JUL 2014 | DOI: 10.1002/ejoc.201402465

      Thumbnail image of graphical abstract

      Eight new sesquiterpenes (phaeusmanes A–H), together with eighteen known analogues, were isolated from the rhizomes of Curcuma phaeocaulis. Their complete structures were elucidated by NMR, MS, and CD spectroscopy. The NO inhibitory effects of the isolates are presented. A possible biogenetic pathway for N-containing eudesmane-type sesquiterpene 8 is postulated.

    3. Nitrogen Heterocycles

      Concise Synthesis of Substituted Quinolizin-4-ones by Ring-Closing Metathesis

      Thomas A. Alanine, Warren R. J. D. Galloway, Thomas M. McGuire and David R. Spring

      Article first published online: 25 JUL 2014 | DOI: 10.1002/ejoc.201402648

      Thumbnail image of graphical abstract

      4H-Quinolizin-4-ones are of significant pharmaceutical interest, yet they are infrequently explored for drug discovery because of difficulties with synthetic accessibility. A new strategy is reported for the synthesis of this rare and biologically interesting class of compounds.

  23. Short Communications

    1. Sequential Reactions

      One-Pot Sequential Schmidt and Ritter Reactions for the Synthesis of N-tert-Butyl Amides

      Nabajyoti Hazarika and Gakul Baishya

      Article first published online: 25 JUL 2014 | DOI: 10.1002/ejoc.201402662

      Thumbnail image of graphical abstract

      A mixture of NaN3/HBF4·OEt2 in AcOH reacts efficiently with aromatic and conjugated (α,β-unsaturated) aldehydes to produce nitrile derivatives, which in situ undergo a Ritter reaction with tert-butyl acetate to afford the corresponding N-tert-butyl amides. The method needs no column chromatography purification, has a wide substrate scope, and uses readily available reagents.

  24. Full Papers

    1. Glycosylation

      Gold(III) Chloride and Phenylacetylene: A Catalyst System for the Ferrier Rearrangement, and O-Glycosylation of 1-O-Acetyl Sugars as Glycosyl Donors

      Rashmi Roy, Parasuraman Rajasekaran, Asadulla Mallick and Yashwant D. Vankar

      Article first published online: 24 JUL 2014 | DOI: 10.1002/ejoc.201402606

      Thumbnail image of graphical abstract

      The Ferrier rearrangement of glycals, and the glycosylation of 1-O-acetyl sugars using an AuCl3/phenylacetylene catalyst system are described. Relay catalysis was observed when phenylacetylene was used in combination with AuCl3. The efficient production of glycosides was achieved in shortened reaction times.

    2. Regiospecific Synthesis

      Regiospecific Synthesis of 7-Hydroxyindoles from Pyrroles by Anionic Benzannulation

      Bidyut Kumar Dinda, Shyam Basak and Dipakranjan Mal

      Article first published online: 24 JUL 2014 | DOI: 10.1002/ejoc.201402486

      Thumbnail image of graphical abstract

      7-Hydroxyindoles have been regioselectively synthesized in good yields by implementation of anionic [4+2] cycloaddition reactions on 2,3-disusbtituted pyrroles. The methodology has also been applied to furan analogues for the synthesis of 7-hydroxybenzofurans.

    3. Asymmetric Catalysis

      Enantioselective Hydrosilylation of Ketones Catalyzed by a Readily Accessible N-Heterocyclic Carbene–Ir Complex at Room Temperature

      Kanako Shinohara, Shun Kawabata, Hanako Nakamura, Yoshiki Manabe and Satoshi Sakaguchi

      Article first published online: 23 JUL 2014 | DOI: 10.1002/ejoc.201402279

      Thumbnail image of graphical abstract

      Stable monodentate NHC–Ir complexes containing hydroxy-amide groups on the side-arm could be synthesized with ease from naturally occurring amino acids such as leucine. Using these complexes, asymmetric hydrosilylation of aryl ketones with diethoxymethylsilane under very mild and flexible conditions readily afforded optically active alcohols with good enantioselectivities (73–96 % ee).

    4. Molecular Synthons

      2,5-Diamide-Substituted Five-Membered Heterocycles: Challenging Molecular Synthons

      Chiara Fabbro, Simone Armani, Laure-Elie Carloni, Federica De Leo, Johan Wouters and Davide Bonifazi

      Article first published online: 23 JUL 2014 | DOI: 10.1002/ejoc.201402654

      Thumbnail image of graphical abstract

      2,5-Diamide-substituted five-membered heterocycles could easily be prepared from the corresponding biscarboxylic acid precursors by means of a Curtius-type rearrangement.

  25. Short Communications

    1. Click Chemistry

      Convenient Access to Carbohydrate–­BODIPY Hybrids by Two Complementary Methods Involving One-Pot Assembly of “Clickable” BODIPY Dyes

      Mayra R. Martinez-Gonzalez, Arlette Urías-Benavides, Enrique Alvarado-Martínez, J. Cristobal Lopez, Ana M. Gómez, Mayca del Rio, Inmaculada Garcia, Angel Costela, Jorge Bañuelos, Teresa Arbeloa, Iñigo Lopez Arbeloa and Eduardo Peña-Cabrera

      Article first published online: 23 JUL 2014 | DOI: 10.1002/ejoc.201402767

      Thumbnail image of graphical abstract

      Two complementary one-pot, three-component methodologies are described that allow the click copper(I)-catalyzed azide–alkyne cycloaddition of azido– or alkyne–carbohydrates with alkyne– or azide–BODIPY derivatives, respectively, and pave the way to water-soluble carbohydrate–difluoroboron-dipyrromethene hybrids.

    2. Natural Product Synthesis

      Application and Scope of Schreiber's Gold(I)-Catalyzed α-Pyrone Synthesis to Ring A Aromatic Podolactones

      Eduardo Sánchez-Larios, Robert D. Giacometti and Stephen Hanessian

      Article first published online: 22 JUL 2014 | DOI: 10.1002/ejoc.201402803

      Thumbnail image of graphical abstract

      Schreiber's gold(I)-catalyzed synthesis of α-pyrones is adapted to the total synthesis of a ring A aromatic analog of urbalactone. The scope of the acetylenic ester partner in the formation of α-pyrones is also studied. Notably, several α-pyrone intermediates from this work exhibit in vitro antiproliferative activity against the A2780 ovarian cancer cell line.

  26. Full Papers

    1. Heterocycles

      Synthesis, Stability, and Photoreactivity of Diazirinyl-Substituted N-Heterocycles Based on Indole, Benzimidazole, and Imidazole

      Björn Raimer, Thomas Wartmann, Peter G. Jones and Thomas Lindel

      Article first published online: 22 JUL 2014 | DOI: 10.1002/ejoc.201402354

      Thumbnail image of graphical abstract

      Benzimidazole leads among N-heterocycles that carry a 2-diazirinyl unit with regard to accessibility and thermal stability. Care is required with the labile imidazole analog; and N-methylated 2-diazirinylindole was also not stable. The investigated 2-diazirines are singlet carbene sources, as confirmed by DFT calculations. Irradiation in the presence of phenol forms the O-, p-, and o-products.

    2. Chiral Pool Synthesis

      A Concise Synthesis of (2R,3R)- and (2R,3S)-3-Hydroxypipecolic Acids, and Total Synthesis of (–)-Deoxoprosopinine and (+)-2-epi-Deoxoprosopinine from D-Glycals

      Asadulla Mallick, Nitee Kumari, Rashmi Roy, Ashokkumar Palanivel and Yashwant D. Vankar

      Article first published online: 22 JUL 2014 | DOI: 10.1002/ejoc.201402603

      Thumbnail image of graphical abstract

      New syntheses of (2R,3R)- and (2R,3S)-3-hydroxypipecolic acids, and total syntheses of (–)-deoxoprosopinine and (+)-2-epi-deoxoprosopinine are reported. The syntheses started from D-glycals, and Ferrier rearrangement, intramolecular cyclization, and Grignard reactions were key steps.

    3. Spiro Compounds

      Synthesis of the Spiroketal Fragment of (–)-Ushikulide A

      Jhillu S. Yadav, N. Mallikarjuna Reddy, Md. Ataur Rahman and Attaluri R. Prasad

      Article first published online: 21 JUL 2014 | DOI: 10.1002/ejoc.201402196

      Thumbnail image of graphical abstract

      The stereoselective synthesis of the spiroketal fragment of (–)-Ushikulide A is described. The key tetrahydropyran moiety was synthesized by using segment-coupled Prins cyclization of an α-acetoxy ether. Both iodohydrin derivatives were obtained from a common THP ring compound by reductive ring cleavage under Boord reaction conditions.

    4. Heteroannulation

      Iron-Promoted Domino Annulation of α-Enolic Dithioesters with Ninhydrin under Solvent-Free Conditions: Chemoselective Direct Access to Indeno[1,2-b]thiophenes

      Suvajit Koley, Sushobhan Chowdhury, Tanmoy Chanda, B. Janaki Ramulu, Ganesh Chandra Nandi and Maya Shankar Singh

      Article first published online: 21 JUL 2014 | DOI: 10.1002/ejoc.201402276

      Thumbnail image of graphical abstract

      The chemoselective synthesis of indeno[1,2-b]thiophenes was developed through the annulation of α-enolic dithioesters with ninhydrin under solvent-free conditions. This domino reaction sequence is highlighted by the use of inexpensive FeCl3·6H2O, its operational simplicity, a short reaction time, its functional-group tolerance, and the concomitant formation of two bonds and one thiophene ring.

    5. Domino Process

      Dual Catalysis in Domino N-Benzylation/Intramolecular C–H Arylation: Regio- and Chemoselective Synthesis of Annelated Nitrogen Heterocycles

      Joydev K. Laha, Neetu Dayal, Swati Singh and Rohan Bhimpuria

      Article first published online: 21 JUL 2014 | DOI: 10.1002/ejoc.201402395

      Thumbnail image of graphical abstract

      A regio- and chemoselective synthesis of fused nitrogen heterocycles is described that proceeds through a domino N-benzylation/C–H arylation reaction sequence. The dual catalysis of this domino process is supported by a mechanistic study.

    6. Nonproteinogenic Amino Acids

      Biocatalytic Synthesis of Enantiopure β-Methoxy-β-arylalanine Derivatives

      Shiming Fan, Shouxin Liu, Hubo Zhang, Ying Liu, Yihuang Yang and Longyi Jin

      Article first published online: 21 JUL 2014 | DOI: 10.1002/ejoc.201402470

      Thumbnail image of graphical abstract

      Chiral β-hydroxy-β-arylalanine and β-methoxy-β-arylalanine derivatives were prepared stereoselectively from ethyl 3-oxo-3-arylpropanoates through oximation, hydrogenation, N-acetylation, methylation, and enzyme-catalyzed hydrolysis.

    7. Multicomponent Reactions

      A Three-Component Reaction for the Synthesis of Diverse, Densely Substituted 2′,3′-Dihydrospiro[indoline-3,6′-[1,3]oxazine]s

      Jing Zhang, Hong Gao, Jing Sun and Chao-Guo Yan

      Article first published online: 21 JUL 2014 | DOI: 10.1002/ejoc.201402500

      Thumbnail image of graphical abstract

      Three-component reactions of α,β-unsaturated N-arylaldimines, dialkyl acetylenedicarboxylate, and N-alkylisatins afforded 3′-aryl-2′-styryl-2′,3′-dihydrospiro[indoline-3,6′-[1,3]oxazine]s in good yields.

    8. Spiroaminals

      Spiroaminals – Crystal Structure and Computational Investigation of Conformational Preferences and Tautomerization Reactions

      Claudia Loerbroks, Birte Böker, Jens Cordes, Anthony G. M. Barrett and Walter Thiel

      Article first published online: 21 JUL 2014 | DOI: 10.1002/ejoc.201402576

      Thumbnail image of graphical abstract

      A joint experimental and computational study reveals the driving forces in the equilibria of spiroaminals. Although thermodynamic and electronic factors such as the anomeric effect lower the energy of the spiroaminal form, steric repulsion in combination with kinetic barriers favor the amine/imine structure. DFT calculations elucidate the mechanism of tautomerization.

    9. Stereoselective Synthesis

      Stereoselective Synthesis of Lignans of Three Structural Types from a Common Intermediate, Enantioselective Synthesis of (+)-Yangambin

      Majid Khalil Syed, Cian Murray and Mike Casey

      Article first published online: 21 JUL 2014 | DOI: 10.1002/ejoc.201402584

      Thumbnail image of graphical abstract

      Construction of a bis(phenylpropanoid) backbone through a one-pot conjugate addition/aldol reaction. Reduction and acid-catalysed cyclisation of the aldol intermediate gave (+)-yangambin in good yield with 2,5-diaryltetrahydrofuran lignans as minor products, whereas the acid-catalysed cyclisation of the aldol intermediate resulted in a derivative of the lignan lirionol.

    10. Ring-Rearrangement Metathesis

      Diversity-Oriented Approach to Carbocycles and Heterocycles through Ring-Rearrangement Metathesis, Fischer Indole Cyclization, and Diels–Alder Reaction as Key Steps

      Sambasivarao Kotha and Ongolu Ravikumar

      Article first published online: 18 JUL 2014 | DOI: 10.1002/ejoc.201402273

      Thumbnail image of graphical abstract

      Dicyclopentadiene derivatives were subjected to ring-rearrangement metathesis to deliver a range of fused polycycle frameworks containing carbocycles, oxacycles, and azacycles. Here, Fischer indole cyclization and the Diels–Alder reaction are employed as key steps.

    11. Cucurbitane Triterpenes

      Roseic Acid and Roseolactones A and B, Furan-Cucurbitane Triterpenes from Russula aurora and R. minutula (Basidiomycota)

      Marco Clericuzio, Giovanni Vidari, Claudio Cassino, Laura Legnani and Lucio Toma

      Article first published online: 18 JUL 2014 | DOI: 10.1002/ejoc.201402208

      Thumbnail image of graphical abstract

      The fruiting bodies of the gilled fungi Russula aurora and R. minutula give a coral pink colour with sulfo-vanillin (SV). We found that they synthesize a few triterpenes, belonging to the seco-cucurbitane series, a rare skeleton type. These compounds show the above reaction with SV on TLC. Assignment of the configurations of 2 and 3 required a thorough ab initio theoretical investigation.

  27. Microreviews

    1. Halonitro Compounds

      Recent Developments in the Chemistry of gem-Halonitro Compounds

      Raquel G. Soengas, Rita C. Acúrcio and Artur M. S. Silva

      Article first published online: 17 JUL 2014 | DOI: 10.1002/ejoc.201402043

      Thumbnail image of graphical abstract

      gem-Halonitro compounds have important practical applications in biology and industry and are also valuable synthetic intermediates of growing chemical interest. In the past few years these derivatives have come to be recognized as powerful synthetic tools. In this review we discuss recent developments in the chemistry of gem-halonitro compounds.

    2. Organocatalysis

      N-Heterocyclic Carbene Catalysis as a Tool for Gaining Access to the 3,4-Dihydropyran-2-one Skeleton

      Domenico C. M. Albanese and Nicoletta Gaggero

      Article first published online: 4 JUL 2014 | DOI: 10.1002/ejoc.201402024

      Thumbnail image of graphical abstract

      Recent years have seen the development of methods for the synthesis of 3,4-dihydropyran-2-ones, known as medicinal agents and building blocks. Progress on N-heterocyclic carbene (NHC) chemistry has given rise to a number of reactive catalytic intermediates, in particular enols/enolates and α,β-unsaturated acylazolium ions, which provide the title compounds through different synthetic pathways.

    3. Glycopeptidomimetics

      From Glycopeptides to Glycopeptoids

      Thomas Szekely, Olivier Roy, Sophie Faure and Claude Taillefumier

      Article first published online: 4 JUL 2014 | DOI: 10.1002/ejoc.201402238

      Thumbnail image of graphical abstract

      Peptoids (N-substituted glycine oligomers) represent a family of peptide mimics in which the side chains are located on the amide nitrogen atoms rather than the α-carbon atoms. The extension of this principle to glycopeptides led to the emergence of glycopeptoids, which can be used not only as hydrolytically stable glycopeptidomimetics, but also as glycoclusters for various binding events.

    4. Organic Solar Cells

      Organometallic Approaches to Conjugated Polymers for Plastic Solar Cells: From Laboratory Synthesis to Industrial Production

      Giuseppe Marzano, Cosimo V. Ciasca, Francesco Babudri, Gabriele Bianchi, Andrea Pellegrino, Riccardo Po and Gianluca M. Farinola

      Article first published online: 1 JUL 2014 | DOI: 10.1002/ejoc.201402226

      Thumbnail image of graphical abstract

      Current organometallic approaches to the synthesis of polymers for plastic solar cells are reviewed, with emphasis also on the requirements for industrial scale-up. The number of synthetic steps for obtaining monomers, the efficiency of the polymerization protocols, and structural simplicity are key to making organic photovoltaics a viable energy source.

    5. Task-Specific Ionic Liquids

      Point-Functionalization of Ionic Liquids: An Overview of Synthesis and Applications

      Cinzia Chiappe and Christian Silvio Pomelli

      Article first published online: 27 JUN 2014 | DOI: 10.1002/ejoc.201402093

      Thumbnail image of graphical abstract

      The versatility of ionic liquids can be conveniently exploited by introducing specific functional groups at selected positions of the cation or anion. These salts (task-specific ionic liquids) can be synthesized through simple and straightforward procedures.

  28. Full Papers

    1. Surface Functionalization

      Diazocines on Molecular Platforms

      Tobias Tellkamp, Jun Shen, Yoshio Okamoto and Rainer Herges

      Article first published online: 24 JUN 2014 | DOI: 10.1002/ejoc.201402541

      Thumbnail image of graphical abstract

      A bridged diazocine has been synthesized whose switching direction is restricted to one side. The diazocine was mounted onto a molecular platform which is known to have a high affinity to gold Au(111) surfaces. Upon irradiation of the thermodynamically more stable cis configuration in solution with light of 385 nm the trans isomer is formed and with green light (530 nm) back-isomerization to the cis form is achieved.

    2. 3-Hydroxypipecolic Acid

      A Short, Chemo-Enzymatic Synthesis of Both Enantiomers of trans-3-Hydroxy­pipecolic Acid

      Stefano Begliomini, Lorenzo Sernissi, Dina Scarpi and Ernesto G. Occhiato

      Article first published online: 16 JUN 2014 | DOI: 10.1002/ejoc.201402258

      Thumbnail image of graphical abstract

      The Suzuki–Miyaura cross-coupling reaction of a lactam-derived enol phosphate, followed by hydroboration/oxidation, is employed for the synthesis of a 2-heteroaryl-3-hydroxypiperidine whose enantiomers are separated by enzymatic kinetic resolution. Both enantiomers are then converted into the corresponding 3-hydroxypipecolic acids, thus obtained in 6 or 7 steps and 15–17 % overall yield.

    3. Iminosugars

      Polyhydroxyamino-Piperidine-Type Iminosugars and Pipecolic Acid Analogues from a D-Mannose-Derived Aldehyde

      Camilla Matassini, Stefania Mirabella, Xhenti Ferhati, Cristina Faggi, Inmaculada Robina, Andrea Goti, Elena Moreno-Clavijo, Antonio J. Moreno-Vargas and Francesca Cardona

      Article first published online: 27 MAY 2014 | DOI: 10.1002/ejoc.201402427

      Thumbnail image of graphical abstract

      The synthesis of diversely substituted polyhydroxypiperidines, polyhydroxyaminopiperidines, and trihydroxypipecolic acid derivatives is reported, using Strecker reactions and double reductive aminations, starting from a D-mannose-derived aldehyde.

  29. Microreviews

    1. Enantioselective Protonation

      Progress in Catalytic Asymmetric Protonation

      Sylvain Oudeyer, Jean-François Brière and Vincent Levacher

      Article first published online: 22 MAY 2014 | DOI: 10.1002/ejoc.201402213

      Thumbnail image of graphical abstract

      This review provides an overview of recent advances in catalytic enantioselective protonation of preformed enol derivatives and catalytically generated enolates or equivalents through various cascade reaction sequences giving access to a large range of enantioenriched compounds containing tertiary stereocentres.

  30. Full Papers

    1. Nucleoside Analogues

      Synthesis and Biological Activity of Triazole-Appended N,O-Nucleosides

      Roberto Romeo, Salvatore V. Giofrè, Caterina Carnovale, Maria A. Chiacchio, Agata Campisi, Raffaella Mancuso, Santa Cirmi and Michele Navarra

      Article first published online: 15 MAY 2014 | DOI: 10.1002/ejoc.201402106

      Thumbnail image of graphical abstract

      1,2,3-Triazole-appended N,O-nucleosides have been synthesized by an approach combining a 1,3-dipolar cycloaddition and an alkyne–azide click chemistry reaction. The synthesized compounds showed antiproliferative activity against tumor cell lines. These nucleoside analogues could be promising scaffolds for the construction of new anticancer agents.

  31. Microreviews

    1. Palladium Catalysis

      Direct Allylic Functionalization Through Pd-Catalyzed C–H Activation

      Frédéric Liron, Julie Oble, Mélanie M. Lorion and Giovanni Poli

      Article first published online: 6 MAY 2014 | DOI: 10.1002/ejoc.201402049

      Thumbnail image of graphical abstract

      This review outlines some selected examples and present challenges relating to palladium-catalyzed direct allylic functionalization. This old reaction, ignored for many years, is enjoying a new age.

  32. Full Papers

    1. Nitrogen Heterocycles

      α-Acryloylamidoalkyl Sulfones in a Synthetic Approach for the Preparation of 6-Alkyltetrahydropyridin-2-ones

      Nicola Lucchetti, Stefano Lancianesi and Marino Petrini

      Article first published online: 23 APR 2014 | DOI: 10.1002/ejoc.201402116

      Thumbnail image of graphical abstract

      The reaction of allylzinc bromides with α-acryloylamidoalkyl sulfones provides straightforward access to the corresponding homoallylamines, which can undergo a ring-closing metathesis reaction to give 6-alkyltetrahydropyridin-2-ones. Homoallylamino derivatives that contain a branched terminal alkene moiety preferentially proceed in a cross-metathesis reaction to give N-substituted fumaramides.

VIEW

  1. 1 - 96

SEARCH

SEARCH BY CITATION